In the field of communications, the need for high-speed transmission of data, including video and audio, has continued to increase. Moreover, there has been an increase in the selection of services by which users can connect to a network, such as the Internet. Specifically, Internet Service Providers (ISPs) may allow for connectivity to the Internet through lower-speed connections at different rates, such as 56 kilobits/second, by employing a Plain Old Telephone Service (POTS) line. Other choices for connection, which are at higher speeds, into a network can include Integrated Services Digital Network (ISDN), Digital Subscriber Line (DSL) service, and cable modem service over a Radio Frequency (RF) cable line. Further, other types of content providers may enable a Subscriber to receive different types of media, such as a video stream, audio stream, etc.
In a typical DSL network, DSLAM (Digital Subscriber Line Aggregation Modules) is employed. A DSLAM is an aggregation device interfacing with customer DSL CPE (customer premise equipment) devices in the downstream and with BRAS devices via ATM or packet links in the upstream. The service providers have ever increasing demand to offer new value added services to DSL customers, such as VOIP (voice over IP), NVOD (near video on demand) and differentiated data services. Significant changes to the current DSL infrastructure need to be made to meet the new requirements.
One such important need is to maximally improve the efficiency of the network connecting the BRAS and the DSLAMs. When new services, such as IP-based broadcast TV or NVOD, are offered, IP multicast technology becomes a natural choice. However, with today's DSL infrastructure, such as infrastructure 100 shown in FIG. 1, the multicast traffic has to be replicated by the BRAS 101 for each individual DSL subscriber (e.g., 102 and 103), resulting in potentially large amounts of duplicate packets sent to each DSLAM, such as DSLAM 104. In this infrastructure as shown in FIG. 1, subscriber termination is performed in a centralized BRAS (e.g., BRAS 101). Typically, no other IP entities exist in the DSL access network (DSLAM 104 is typically not IP capable and a home gateway is often not present). There is also no control data exchange between BRAS 101 and other entities in the DSL access network, such as DSLAM 104 and home gateways 102 and 103. Furthermore, quality of service (QoS) is provided within BRAS 101 and it is not distributed to other entities.